1. Field of the Invention
The present invention relates to an image processing device, an image processing method, and an image processing program. The present invention relates more specifically to an image processing device, an image processing method, and an image processing program, which are used when obtaining bitmap data by converting data where security functions are set up.
2. Description of the Related Art
A technology has been established for setting up security functions that limit operations on document files in order to maintain confidentiality of the documents. For example, a PDF (Portable Document Format) file can be provided with a function to prevent a user from opening it unless the user enters a proper password or a function to clarify the author's identity.
As one of the technologies using such security functions, a file conversion device was proposed (see Unexamined Publication No. JP-A-2002-297491), which, upon receiving a request for printing the contents having an identifier specifying the output destination, e.g., a network address, converts the contents into a PDF file using said identifier as the password.
The file conversion device maintains the security of the document file to be printed while handling the transferred data until it reaches the printing device.
When a document file is transmitted to the printing device to be printed via a printer controller, said document file is converted into bitmap data, i.e., bitmapped image data by rasterization. The bitmap data thus obtained is printed on paper as well as saved in the printer controller.
However, since the operation limiting information that denotes the limitations of operations concerning said document file drops out during the process of rasterizing a document file in which security functions are set up, the process ends up storing the bitmap data having no security function set up in the printer controller.
Therefore, the saved bitmap data allows any person to view, print and modify it through applications such as Job Spooler Utility, etc. This is a problem as it allows a free use of the bitmap data which has the identical contents as those of the document file in which security functions are set up, essentially resulting in a loss of security for the document file.